Of the three, Chirp is the hardest one for me. Nona is the easiest one, since I have no trouble catching her. Kinda wierd, considering that I once actually got injured trying to help anarchist_nomad catch her. Times have changed! Once she realized what I wanted to do, of course, she wasn't very happy about it, and the process would have been as awful as it was before she adopted me, but since I'd already caught her, no traumatic chase ensued, and she didn't struggle or complain at all, unlike her sisters.